Motor vehicle has become one of the most important applications in modern development along with the advancement of technologies. However, the road systems have grown very complicated due to the rapid expansion of the cities. Thus, different navigation systems (for example, the global positioning system (GPS) and the traffic message channel (TMC)) have been invented and brought us a lot of conveniences. An existing in-car navigation device not only provides guidance on roads and sites but also allows a driver to understand the current driving status and the position, direction, and speed of the vehicle.
Generally speaking, a driver driving in a highway usually follows the guidance of a GPS navigator, and the GPS navigator gives a sound to notify the driver when the vehicle is about to reach an access road. For example, when the vehicle is about to reach the destination, the GPS navigator instructs the driver to turn left or right. However, the driver may still miss the destination if the driver does not realize that the current driving lane is not a turn lane.
Additionally, a navigation system usually cannot get to know the road condition of a current driving lane or whether the current driving lane is open. Thus, the driver has to pay attention on the road condition ahead in the current driving lane. The driver may be fined if the driver accidentally enters an unallowable lane (for example, a bus lane or a lane open to the opposite direction in rush hours). Moreover, the safety of the driver may be jeopardized if an accident occurs or a construction is going on ahead in the current driving lane.